title: Disappearing hyperdense middle cerebral artery sign in ischaemic stroke patients treated with intravenous thrombolysis: clinical course and prognostic significance.
abstract: OBJECTIVE
  Hyperdense middle cerebral artery sign (HMCAS) on CT is a well known indication of thromboembolic arterial occlusion. Its disappearance after thrombolytic therapy is poorly described. Taking the rate of HMCAS disappearance as a surrogate for MCA recanalisation, its prognostic value after intravenous thrombolysis was examined.
  
  
  METHODS
  1905 stroke patients with HMCAS on admission CT scan in the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Register (SITS-ISTR) were studied. On follow-up CT scans 22-36 h after thrombolysis, HMCAS disappeared in 831 cases, persisted in 788 and was uncertain in 122; follow-up CT was not done in 164 cases.
  
  
  RESULTS
  Patients whose HMCAS disappeared were younger (median age 67 years vs 69 years for persistent; p = 0.03), with milder stroke (admission National Institute of Health Stroke Scale (NIHSS) score was 16 vs 17; p<0.005) and were less likely to have early infarct signs on admission CT (26% vs 33%; p<0.005). Patients with disappearing HMCAS were more likely to have early improvement in NIHSS score (median improvement 2 vs 0 at 2 h; 4 vs 1 at 24 h), be independent at 3 months (42% vs 19%), with fewer deaths (15% vs 30%) than those with persistent HMCAS. In multivariate analysis, HMCAS disappearance independently predicted functional independence and survival. Early NIHSS improvement independently predicted HMCAS disappearance.
  
  
  CONCLUSIONS
  HMCAS disappeared after intravenous thrombolysis in about half of cases and these patients had twice as good outcomes compared with those with persistent HMCAS. The prognosis in patients with MCA occlusion that persists after intravenous thrombolysis is poor, which may indicate the need for an alternative treatment approach to this subgroup.
authors.affiliation: Department of Neurology, Karolinska University Hospital- Solna, SE-171 76 Stockholm, Sweden. tatiana.kharitonova@ki.se
authors.forename: T
authors.initials: T
authors.lastname: Kharitonova
authors.forename: M
authors.initials: M
authors.lastname: Thorén
authors.forename: N
authors.initials: N
authors.lastname: Ahmed
authors.forename: J M
authors.initials: JM
authors.lastname: Wardlaw
authors.forename: R
authors.initials: R
authors.lastname: von Kummer
authors.forename: L
authors.initials: L
authors.lastname: Thomassen
authors.forename: N
authors.initials: N
authors.lastname: Wahlgren
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000401:mortality; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator